Hydrocarbons are often produced from well bores by sucker rod pumps. Beam pumping, or the sucker-rod lift method, is the oldest and most widely used type of artificial lift for most wells. A sucker-rod pumping system is made up of several components, some of which operate aboveground and other parts of which operate underground, down in the well. The surface-pumping unit, which drives the underground pump, consists of a prime mover (usually an electric motor) and, normally, a beam fixed to a pivotal post. The post is called a Sampson post, and the beam is normally called a walking beam. This system allows the beam to rock back and forth, moving the downhole components up and down in the process. The entire surface system is run by a prime mover, V-belt drives, and a gearbox with a crank mechanism on it. Linked rods attached to an underground pump are connected to the surface unit. The linked rods are normally called sucker rods and are usually long steel rods, from ⅝ to more than 1 or 1¼ in. in diameter. The steel rods are normally screwed together in 25- or 30-ft lengths to become a continuous length from the surface to the downhole pump. The steel sucker rods typically fit inside the tubing and are stroked up and down by the surface-pumping unit. This activates the downhole, positive-displacement pump at the bottom of the well. Each time the rods and pumps are stroked, a volume of produced fluid is lifted through the sucker-rod tubing annulus and discharged at the surface.
A polished rod is the top-most rod in a rod string, this polished rod, as the other rods in the string is subject to the movement generated by the reciprocating walking beam, but different to the other rods and due to its position at the surface, the polished rod will slide in and out of the tubing via a stuffing box that forms a tight seal with the polished rod and diverting the produced fluids out of the pumping tee into the flow line. As the only part of the rod string in direct contact with the ambient during the normal operation of the artificial lift unit, it has become one of the ways well operators determine the status of a artificial lift system. By manually gauging the temperature of the polished rod during normal operation of the system, a well operator can infer or detect issues such as:
Excessive tightness of the sealing gland.
Lack of well fluid at the top of the well.
Pump off conditions.
Polished rod alignment.
All the above mentioned conditions cause strain, wearing and eventually an increase of temperature in the stuffing box sealing gland that divert the produced fluids out of the pumping tee into the flowline. If the root cause of the problem causing a temperature increase in the polished rod is not identified and corrected, and once the sealing gland is damaged, the production fluids will escape out of the pumping tee.
The current methods to gauge the polished rod temperature vary from manually touching the rod and approximate the temperature by feeling the heat emanated by it to a lapsed patent (U.S. Pat. No. 4,672,845) of a complicated housing with temperature sensors fixed to the stuffing box. These methods are, in general inaccurate and in particular:
A. Manual sensing:
                a. Unsafe conditions associated with:        i. Possible high temperature of the polished rod>200□.        ii. Physical contact with moving parts during operation.        b. Logistics:        i. Well operator has to be present to detect issues.        ii. Manpower and vehicles operating costs.B. Contact autonomous sensing. Depending on the position in which the contact sensor is located, to different and undesirable effects will occur:        a. “Average” readings: As the polished rod is moving in and out of the stuffing box, if the sensor is statically located on top of said box the reading will be an average of the temperature in the rod. This average will be affected by the speed of the well and the reaction time of the sensor.        b. “Section” readings: If the sensor is installed in a way that moves with the polished rod it will have to be installed on the very top part of it, limiting the temperature reading to that particular section of the rod.        
For at least the foregoing reasons, there remains a need for an apparatus that is easily installed and can:
1. Detect the temperature of several points of the polished rod at the same time.
2. Automatically identify the pumping tee and the polished rod.
3. Stop the well operation automatically in the case of an alarm condition.
4. Notify the well operator if an alarm condition is found.
5. Provided remote data collection, visualization and operation.